Pepper Roux wakes up on the morning of his 14th birthday knowing he's going to die. His end has been predicted by his pious Aunt Mireille, who was given the information by St Constance in a vision. As the day begins, Pepper decides that, instead of waiting around to see what happens, he will run away to sea; and so begins a game of catch-me-if-you-can with Death himself.

Pepper hides out in other people's identities. He becomes his own father – a drunken sea captain – a telegram boy, a Carmargue "guardian", a journalist and a foreign legionnaire. He meets sailors, scamsters, prostitutes and a cross-dressing first mate. But no matter where he goes, Death is always just around the corner.

The captain's commission is an insurance scam, a leaky death ship. As a telegram boy he's mostly delivering notifications of death from the war in Algeria. On the newspaper, it's all destruction and murder. But maybe it's Pepper's enhanced awareness of Death's proximity that makes him more vividly alive than the people around him.

If that makes the book sound dark and deep, well, it does touch on dark and deep things, but then it bounces back into the light. The story travels like a brilliantly skimmed stone, spinning through the air, kissing the water before spinning off again. It has all the headlong, cocky velocity of Pepper's own escape. At crucial moments it is driven by pure cheek. When Pepper, aged 14, passes himself off as a sea captain, our narrator shrugs and says: "People see what they expect to see, don't they?"

The book harnesses all the joyous weirdness of its setting – the Carmargue, with its wild horses, improbable flamingoes and that strange, medieval space station of a town, Aigues-Mortes. But most of all it has the McCaughrean sentences. I can't think of anyone working in the English language who writes a better sentence.

Describing the way Pepper's mother and aunt dominated his life, McCaughrean says: "the women leaned in against Pepper's childhood like a pair of book ends – big, ponderous women so full of tragedy they could barely make their corsets hook up".

The newspaper where Pepper works is a silo where "he hopes the words will close over him like grain and hide him from sight". I don't know how long it takes her to write these but they whistle past your ear like bullets and leave you tingling with pleasure.

McCaughrean has had a brilliant career. She has won the Whitbread three times, and the Carnegie. She was chosen to write the official sequel to Peter Pan. If she doesn't have the high profile you'd expect, that may be because she doesn't repeat herself, and so has not become a brand. Like Pepper she takes on a different identity for each book.

She's written masterly stories about the medieval theatre, the coming of the American railways, and Antarctic exploration. The one thing you're not expecting from someone who has achieved so much is for her to raise her game. But that's what she has done. I think this may be her best yet.

The publisher's blurb compares Pepper Roux to the movie Amélie, largely because they're both set in France. This is like comparing the siege of Stalingrad to the Eurovision song contest because they both involve Russians and Germans. Pepper Roux is much funnier, much more stylish and much more profound. If you want to compare it to something else you could try Borges or García Márquez.